// Do this as the first thing so that any code reading it knows the right env.
process.env.BABEL_ENV = "development";
process.env.NODE_ENV = "development";

// Makes the script crash on unhandled rejections instead of silently
// ignoring them. In the future, promise rejections that are not handled will
// terminate the Node.js process with a non-zero exit code.
process.on("unhandledRejection", err => {
    throw err;
});

// Ensure environment variables are read.
require("../config/env");

const fs = require("fs");
const chalk = require("react-dev-utils/chalk");
const webpack = require("webpack");
const WebpackDevServer = require("webpack-dev-server");
const clearConsole = require("react-dev-utils/clearConsole");
const checkRequiredFiles = require("react-dev-utils/checkRequiredFiles");
const { choosePort, createCompiler, prepareProxy, prepareUrls } = require("react-dev-utils/WebpackDevServerUtils");
const openBrowser = require("react-dev-utils/openBrowser");
const paths = require("../config/paths");
const configFactory = require("../config/webpack.config");
const createDevServerConfig = require("../config/webpackDevServer.config");

const useYarn = fs.existsSync(paths.yarnLockFile);
const isInteractive = process.stdout.isTTY;

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
    process.exit(1);
}

// Tools like Cloud9 rely on this.
const DEFAULT_PORT = parseInt(process.env.PORT, 10) || 4017;
const HOST = process.env.HOST || "0.0.0.0";

if (process.env.HOST) {
    console.log(
        chalk.cyan(`Attempting to bind to HOST environment variable: ${chalk.yellow(chalk.bold(process.env.HOST))}`)
    );
    console.log(`If this was unintentional, check that you haven't mistakenly set it in your shell.`);
    console.log(`Learn more here: ${chalk.yellow("https://bit.ly/CRA-advanced-config")}`);
    console.log();
}

// We require that you explicitly set browsers and do not fall back to
// browserslist defaults.
const { checkBrowsers } = require("react-dev-utils/browsersHelper");
checkBrowsers(paths.appPath, isInteractive)
    .then(() => {
        // We attempt to use the default port but if it is busy, we offer the user to
        // run on a different port. `choosePort()` Promise resolves to the next free port.
        return choosePort(HOST, DEFAULT_PORT);
    })
    .then(port => {
        if (port == null) {
            // We have not found a port.
            return;
        }

        const config = configFactory("development");
        const protocol = process.env.HTTPS === "true" ? "https" : "http";
        const appName = require(paths.appPackageJson).name;
        const useTypeScript = fs.existsSync(paths.appTsConfig);
        const tscCompileOnError = process.env.TSC_COMPILE_ON_ERROR === "true";
        const urls = prepareUrls(protocol, HOST, port, paths.publicUrlOrPath.slice(0, -1));
        const devSocket = {
            warnings: warnings => devServer.sockWrite(devServer.sockets, "warnings", warnings),
            errors: errors => devServer.sockWrite(devServer.sockets, "errors", errors)
        };
        // Create a webpack compiler that is configured with custom messages.
        const compiler = createCompiler({
            appName,
            config,
            devSocket,
            urls,
            useYarn,
            useTypeScript,
            tscCompileOnError,
            webpack
        });
        // Load proxy config
        const proxySetting = require(paths.appPackageJson).proxy;
        const proxyConfig = prepareProxy(proxySetting, paths.appPublic, paths.publicUrlOrPath);
        // Serve webpack assets generated by the compiler over a web server.
        const serverConfig = createDevServerConfig(proxyConfig, urls.lanUrlForConfig);
        const devServer = new WebpackDevServer(compiler, serverConfig);
        // Launch WebpackDevServer.
        devServer.listen(port, HOST, err => {
            if (err) {
                return console.log(err);
            }
            if (isInteractive) {
                clearConsole();
            }

            // We used to support resolving modules according to `NODE_PATH`.
            // This now has been deprecated in favor of jsconfig/tsconfig.json
            // This lets you use absolute paths in imports inside large monorepos:
            if (process.env.NODE_PATH) {
                console.log(
                    chalk.yellow(
                        "Setting NODE_PATH to resolve modules absolutely has been deprecated in favor of setting baseUrl in jsconfig.json (or tsconfig.json if you are using TypeScript) and will be removed in a future major release of create-react-app."
                    )
                );
                console.log();
            }

            console.log(chalk.cyan("Starting the development server...\n"));
            openBrowser(urls.localUrlForBrowser);
        });

        ["SIGINT", "SIGTERM"].forEach(function(sig) {
            process.on(sig, function() {
                devServer.close();
                process.exit();
            });
        });

        if (isInteractive || process.env.CI !== "true") {
            // Gracefully exit when stdin ends
            process.stdin.on("end", function() {
                devServer.close();
                process.exit();
            });
            process.stdin.resume();
        }
    })
    .catch(err => {
        if (err && err.message) {
            console.log(err.message);
        }
        process.exit(1);
    });
